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Old 28th January 2007, 07:31 PM   #71
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Impressive indeed, how does it sound, or more appropriately, not sound?

-Rob
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Old 28th January 2007, 07:32 PM   #72
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I still didn't listened to it, I only listened to the sound of relays switching

As I also have a Placette and will be able to compare both.

I won't hide that my intention here was to create the best sounding remote controlled attenuator possible. If it checks out well, I might arrange for silver/teflon in relay switching boards.

The calculator was posted here: http://www.diyaudio.com/forums/showt...215#post840215 and you can use any resistor values you may choose (however, they need to multiply by 2). This calculator was created by Algar_emi.
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Old 29th January 2007, 03:50 PM   #73
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What do the boards and parts tally up to? Will you be selling the compete kit? Are you machining some nice faceplates for the display and knob?

-Rob
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Old 29th January 2007, 04:26 PM   #74
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The relays are approx $3 ea, nude Vishays are either $11.50 from Percy or $7.50 directly from TI. You can also use Caddocks MK132 at $4ea.

The relay PCBs would be $20/set, the control board with microchip and display need to be sourced from Veteran.

The HP encoder is probably $70, but you can get a cheaper one as well.

At some time in a future, I will be probably offering a complete kit.

This type of attenuator is best to use directly at amp's input. If the product becomes succesful I may consider some nice enclosure, but it's still a long way from this point.
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Old 29th January 2007, 07:36 PM   #75
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Beautiful work Peter. I'm interested if you end up offering a kit. I need six channels.
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Old 29th January 2007, 07:44 PM   #76
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Peter:

Did a bit of searching but couldn't find the "Veteran" you mention as supplier for the Controller/Display parts.

Got Link?

-Rob
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Old 29th January 2007, 07:49 PM   #77
reever is offline reever  United States
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Veteran is a member here.....


http://www.unisonus.com/
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Old 29th January 2007, 07:58 PM   #78
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Ahhh... Thank-you kind sir.

-RT
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Old 29th January 2007, 08:36 PM   #79
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hi peter,

do you have any idea how this relay attenuator handles dc offset? another relay attenuator i use requires the use of coupling capacitors to remove the dc as with a dc offset of only 5 mV it "pops" at steps where all the relays move at once.

i would be very interested in this relay if i allows me to avoid the use of coupling caps. actually, i'm interested either way but the ability to handle some dc offset would be fantastic.

thanks
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Old 29th January 2007, 09:06 PM   #80
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Here is the relay datasheet: http://pewa.panasonic.com/pcsd/produ...pdf_cat/tq.pdf

As to the attenuator configuration, it is analog to a potentiometer. The good thing about it is that the resistors are not switched in and out, but the chain of resistors (series and shunt) is shorted by relays what reduces switching noise.

The schematic was posted here: http://www.audio.webd.pl/pdf/pvc_sch.pdf
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